Sectionalized arrow

ABSTRACT

A sectionalized arrow includes a tubular-shaped tip section and a tubular-shaped nock section. Structurally, the aft-end of the tip section is formed with a chamber, and the fore-end of the tip section is formed with an insert. Essentially, the insert of the nock section and the chamber of the tip section have the same length “L”. A shim or strip of coating is positioned on the insert of the nock section to force contact between the insert and the chamber to establish a snug fit between the tip section and the nock section.

FIELD OF THE INVENTION

The present invention pertains generally to arrows that are suited foruse with man-powered weapons, such as a conventional bow, a compound bowor a crossbow. More particularly, the present invention pertains toarrows that can be assembled, onsite, by the user. The present inventionis particularly, but not exclusively, useful as an arrow that can bebroken down into sections for ease of transport, and subsequentlyassembled, as desired, to establish an aerodynamically suitable arrow.

BACKGROUND OF THE INVENTION

When so-called “man-powered” weapons, such as a crossbow or a compoundbow, are used for hunting or target shooting, a person will usuallycarry most of the equipment required for participating in theseactivities. Typically, the primary means of transportation for theseactivities will be travelling on foot. In most instances, a person willcarry the weapon, arrows, spare parts, and tools required to use orservice the weapon. Further, for hunting activities, a hunter will mostlikely spend several hours, and may very well spend several days, in anisolated area. When this is the case, the amount of supplies requiredincreases significantly to include food, water, and shelter.

In the case of target shooting or hunting, it is of great benefit tohave the ability to pack efficiently and compactly. Indeed, varioustypes of the equipment that is used for these activities have beenmodified for the specific purpose of allowing more equipment to take upless space. For instance, a deflated air mattress takes up a minimalamount of space, as does a set of collapsible eating utensils. One pieceof equipment, however, that has not been modified in this manner is anarrow for a man-powered weapon. Arrows, with lengths approaching threefeet when fully assembled, require special carrying pouches or devicesthat take up a significant amount of space and require special handlingto avoid breakage or damage.

In light of the above, it is an object of the present invention toprovide an arrow that can be carried in sections and then rapidlyassembled. Another object of the present invention is to provide adisassembled arrow that can be transported and then easily assembled tobe aerodynamically stable during use. Yet another object of the presentinvention is to provide an arrow that is easy to use, is relativelysimple to manufacture, and is relatively cost effective.

SUMMARY OF THE INVENTION

In accordance with the present invention, a two-part sectionalized arrowis provided that can be assembled by joining a nock section with a tipsection. In overview, the tip section and the nock section are bothelongated shafts having a respective fore-end and a respective aft-end.For their assembly, an insert is formed onto the fore-end of the nocksection, and a hollow chamber is formed into the aft-end of the tipsection. A shim that is attached to the insert and is positioned betweenthe insert and the inside of the hollow chamber promotes an interactionbetween the insert and the chamber that establishes a snug fit betweenthe two sections when the insert of the nock section is received intothe aft-end of the tip section.

Structurally, the nock section of the arrow of the present inventiondefines an elongated, tubular-shaped shaft that defines an axis. Atubular-shaped insert portion is formed at the fore-end of the nocksection, and it is oriented to extend axially away from the fore-end ofthe nock section. This insert portion has an outside diameter “d_(i)”,and it has a length “L”. A nock and stabilizing fins of a typewell-known in the pertinent art are located at the aft-end of the nocksection.

Like the nock section of the arrow, the tip section of the arrow is alsoan elongated, tubular-shaped shaft, and it defines an axis. As indicatedabove, a hollow chamber is formed into the aft-end of the tip sectionthat is dimensioned and configured to receive the insert of the nocksection.

Dimensionally, the tip section has an outer diameter “D” and the hollowchamber in the tip portion has a diameter “d_(c)” that is measured toits inner surface. Importantly, “d_(c)” of the chamber is slightlylarger (e.g. 0.0025 cm or 0.001 inches) than “d_(i)” of the insert toallow for the insertion of the insert into the hollow chamber whenassembling the arrow.

An important component of the present invention is a longitudinal shimor strip of coating material that is preferably located on the insertportion of the nock section. As envisioned for the present invention,when sections of the arrow are joined together, the shim or strip ofcoating material will be positioned between the inside surface of thehollow chamber of the tip section and the outer surface of the insertportion of the nock section. As a consequence, the shim will force alarge fraction of the outer surface of the insert into contact with theinner surface of the chamber to establish a snug fit between the two.

The arrow of the present invention also includes a mechanical stop thatis used to limit the forward movement of the insert of the nock sectioninto the hollow chamber of the tip section. In one embodiment, themechanical stop is an annular-shaped collar that is affixed to the nocksection at a distance “L” from the fore-end of the nock section. Forthis embodiment, the collar has an outer diameter “D” that is equal tothe outer diameter “D” of the tip section. For an alternate embodiment,the mechanical stop is a tubular-shaped interior sleeve that is affixedinside the chamber of the tip section. For this embodiment, the sleeveis positioned at a distance “L” from the aft-end of the tip section. Theinterior sleeve is constructed to have an inner diameter that is smallerthan the diameter of the insert, “d_(i).” For either embodiment, themechanical stop limits the forward movement of the insert of the nocksection into the hollow chamber of the tip section.

It is well-known that the aerodynamic performance of an arrow improveswith the straightness of an arrow. Thus, in accordance with the presentinvention, a simple procedure is provided to ensure the sectionalizedarrow is as straight as possible, when assembled. To accomplish this,analyses of both the tip section and the nock section of an arrow areconducted to identify their respective planes of curvature after eachsection of the arrow has been manufactured. These two planes ofcurvature are then oriented next to one another in a coplanararrangement. When the two sections are coplanar, they can be oriented sothe net effect of the curvature on the assembled arrow is minimized.Specifically, as with any arrow, the goal here is to minimize the effectof curvature. Once the planes are aligned in this way, a first indexmark is placed onto the fore-end of the nock section and a second markis placed on the aft-end of the tip section. Further, in order to ensurethese same sections are used with each other when there is a set ofarrows, the marks for each particular arrow may be color coded.Operationally, these index marks can then be aligned by a user during alater assembly of the arrow to ensure the effect of curvature isminimized.

To construct the sectionalized arrow, the insert of the nock section isinserted into the hollow chamber of the tip section. As the insert ismoving forward into the hollow chamber, the shim or strip of coatingmakes contact with the inner surface of this hollow chamber. This actionestablishes contact between the insert and the hollow chamber to producea snug fit. Once the insert makes contact with the mechanical stopinside the hollow chamber, the arrow is assembled. As a final step, thesections are rotated so that the index marks on the respective nock andtip sections are aligned next to one another. This rotation of thesections produces as straight of an arrow as possible for thisparticular set of sections.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1 is a perspective view of an assembled arrow in accordance withthe present invention;

FIG. 2A is an exploded view of the arrow of the present invention asseen along the line 2-2 in FIG. 1, showing an insert of one arrowsection positioned for insertion into the chamber of another arrowsection;

FIG. 2B is an assembled view of the insert and chamber shown in FIG. 2A;

FIG. 3 is a cross section view of the sectionalized arrow of the presentinvention as seen along the line 3-3 in FIG. 2B;

FIG. 4 is a cross section view of the sectionalized arrow of analternate embodiment of the present invention as seen along the line 3-3in FIG. 2B;

FIG. 5A is an exploded view of an alternate embodiment of the arrow ofthe present invention as seen along the line 2-2 in FIG. 1, showing aninsert of one arrow section positioned for insertion into the chamber ofanother arrow section;

FIG. 5B is an assembled view of the insert and chamber shown in FIG. 5A;

FIG. 6 is an exploded view of sections of the arrow of the presentinvention oriented for aerodynamic alignment; and

FIG. 7 is a perspective view of an alternate embodiment of an assembledarrow in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1, a sectionalized arrow in accordance withthe present invention is shown and is generally designated 10. As shown,the arrow 10 includes a tip section 12 and a nock section 14. Further,the tip section 12 has a fore-end 16 and an aft-end 18. Similarly, thenock section 14 has a fore-end 20 and an aft-end 22.

In FIG. 2A it will be seen that the tip section 12 is essentially ahollow, tubular-shaped structure that is formed with a chamber 24 insidethe aft-end 18 of the tip section 12. Further, the tip section 12 isshown to have an outer diameter “D”, and the chamber 24 is shown to havea diameter “d_(c)”. Similarly, it will be seen in FIG. 2A that, like thetip section 12, the nock section 14 is also essentially a hollow,tubular-shaped structure. The nock section 14, however, is formed withan insert 28 that extends axially from the fore-end 20 of the nocksection 14. As shown, the insert 28 has a length “L” and it has an outersurface 30 with a diameter “d_(i)”. In comparison, the diameter “d_(c)”of chamber 24 of the tip section 12 will be slightly larger than thediameter “d_(i)” of the insert 28. Typically, the difference d_(c)−d_(i)will be approximately one thousandth of an inch (d_(c)−d_(i)≅0.001inch).

Still referring to FIG. 2A it will be seen that a shim or strip ofcoating 32 is positioned on the outer surface 30 of the insert 28. Aswill be appreciated with reference to FIG. 2B, when the insert 28 isinserted into the chamber 24, the shim 32 effectively fills in thedifference d_(c)−d_(i) between the inner surface 26 of the tip section12 and the outer surface 30 of the nock section 14. The result when thearrow 10 is assembled is a “snug” interference fit between the tipsection 12 and the nock section 14 in the vicinity of the shim 32 thatimpedes a rotation of the tip section 12 relative to the nock section14. FIG. 3 shows such a fit when a single shim 32 is used for thispurpose. FIG. 4 shows that a plurality of shims 32 (i.e. shims 32 a, 32b and 32 c) can be employed for this same purpose, if desired.

Referring to both FIG. 2A and FIG. 2B it will be seen that the nocksection 14 includes a mechanical stop 34 that is affixed at its fore-end20. Specifically, the mechanical stop 34 is preferably an annular-shapedcollar, and its purpose is to limit the extent to which the insert 28 ofnock section 14 can be inserted into the chamber 24 of the tip section12. Specifically, the stop 34 limits this insertion to the length “L” ofthe insert 28. In an alternate embodiment as shown in FIGS. 5A and 5B,an equivalent structure is used, in lieu of the mechanical stop 34. Forthis alternate embodiment, a sleeve 36 is used. Preferably, the sleeve36 is annular-shaped with an inner diameter “d_(s)” and it is affixed tothe inner surface 26 of the chamber 24, at the distance “L” from theaft-end 18 of the tip section 12. Again, like the mechanical stop 34,the purpose of the sleeve 36 is to limit the extent to which the insert28 of nock section 14 can be inserted into the chamber 24 of the tipsection 12.

Referring now to FIG. 6, a scheme is presented for aerodynamicallyaligning the tip section 12 with the nock section 14, when the arrow 10is assembled. The need for this alignment comes from the fact that bothof the tubular-shaped sections (i.e. tip section 12 and nock section 14)are subject to being bent, even if ever so slightly, during theirmanufacture. Such bends can be easily detected. In fact, it will happen,when the tip section 12 and nock section 14 are placed on a planesurface, they will roll on the plane surface until their respectiveplanes of curvature become substantially parallel to the plane of thesurface on which they are placed. For such a condition, as shown in FIG.6, a slight bend of nock section 14 will manifest itself as thedeflection “Δ₁”. Similarly, a bend of tip section 12 will manifestitself as the deflection “Δ₂”. By orienting the tip section 12 and thenock section 14 with their respective deflections “Δ₂” and “Δ₁” counterto each other (i.e. off-set), the straightness of the arrow 10 isoptimized when it is assembled. To provide replication of thisalignment, the index marks 38 a and 38 b are provided.

As envisioned for the present invention, an assembly of arrow 10 isaccomplished by inserting the insert 28 of the nock section 14 into thechamber 24 of the tip section 12. The nock section 14 can then berotated relative to the tip section 12 through an angle “θ” until theindex mark 38 a is aligned with (i.e. adjacent to) the mark 38 b. Withthis rotation, the aerodynamic straightness of the arrow 10 isoptimized.

FIG. 7 shows an alternate embodiment for the present invention whereinthe arrow 10 includes an intermediate section 40 that is positionedbetween the tip section 12 and the nock section 14. As will beappreciated by the skilled artisan, the intermediate section 40 willinclude structure at one of its ends that is equivalent to the insert 28disclosed above for the nock section 14. And, it will include structureat the other end that is equivalent to the chamber 24 of the tip section12.

While the particular Sectionalized Arrow as herein shown and disclosedin detail is fully capable of obtaining the objects and providing theadvantages herein before stated, it is to be understood that it ismerely illustrative of the presently preferred embodiments of theinvention and that no limitations are intended to the details ofconstruction or design herein shown other than as described in theappended claims.

What is claimed is:
 1. A shaft for an arrow which comprises: anelongated, tubular tip section defining an axis and having a fore-endand an aft-end, wherein the tip section has an outer diameter “D” and isformed with a chamber at the aft-end thereof, and wherein the chamberhas a diameter “d_(c)” measured at an inner surface of the chamber; anelongated, tubular nock section having a fore-end and an aft-end,wherein the nock section is formed with an insert extending in an axialdirection from the fore-end of the nock section through a distance “L”,wherein the insert of the nock section has an outer surface with adiameter “d_(i)”, wherein d_(i) is less than d_(c)(d_(i)<d_(c)) forinsertion of the insert of the nock section into the chamber of the tipsection; a mechanical stop interacting between the tip section and thenock section for limiting an insertion of the insert into the chamber ofthe tip section; and a shim affixed to the outer surface of the insertof the nock section to position the shim between the outer surface ofthe insert and the inner surface of the chamber to force contact betweenthe outer surface of the insert and the inner surface of the chamber toestablish a snug fit therebetween when the tip section and nock sectionare assembled to form the shaft.
 2. A shaft as recited in claim 1wherein the mechanical stop is an annulus-shaped collar affixed to thefore-end of the nock section adjacent the insert, wherein the collar hasthe diameter “D”.
 3. A shaft as recited in claim 1 wherein themechanical stop is an annulus-shaped interior sleeve affixed inside thechamber of the tip section at a distance “L” from the aft-end of the tipsection, wherein the sleeve has an inner diameter “d_(s)” with “d_(s)”being less than “d_(i)” (“d_(s)”<“d_(i)”<“d_(c)”).
 4. A shaft as recitedin claim 1 wherein the shim is made of amyl acetate.
 5. A shaft asrecited in claim 4 wherein the shim is a first shim and the shaftfurther comprises: a second shim affixed to the outer surface of theinsert of the nock section to position the second shim between the outersurface of the insert and the inner surface of the chamber; and a thirdshim affixed to the outer surface of the insert of the nock section toposition the third shim between the outer surface of the insert and theinner surface of the chamber, wherein the second shim and the third shimcooperate with the first shim to force contact between the outer surfaceof the insert and the inner surface of the chamber to establish the snugfit therebetween.
 6. A shaft as recited in claim 5 wherein the firstshim, the second shim, and the third shim are spaced equidistantly fromeach other on the outer surface of the insert.
 7. A shaft as recited inclaim 1 wherein the snug fit is established by cooperation of theinsert, the chamber, and the shim.
 8. A shaft as recited in claim 1further comprising a middle section having a fore-end and an aft-endpositioned between the tip section and the nock section, wherein asecond insert is formed onto the fore-end of the middle section and isreceived by the chamber of the tip section, and wherein the aft-end ofthe middle section is formed with a second hollow chamber to receive theinsert of the nock section.
 9. A shaft as recited in claim 1 wherein afirst index mark is placed on the aft-end of the tip section foralignment with a second mark placed on the fore-end of the nock sectionto aerodynamically align the tip section with the nock section during anengagement of said sections.
 10. A shaft as recited in claim 9 whereinthe second index mark is placed onto the collar of the tip section. 11.An arrow which comprises: an elongated, tubular shaft defining an axis,wherein the shaft includes a tip section having an aft-end and afore-end and a nock section having an aft-end and a fore-end, whereinthe aft-end of the tip section has an outer diameter “D” and is formedwith a chamber having an inner diameter “d_(c)” measured at an innersurface; an insert integrally formed onto the aft-end of the nocksection, wherein the insert extends axially from the fore-end of thenock section and has an outer surface with a diameter “d_(i)”, and alength “L”, and wherein the insert is received into the chamber of thetip section; and a shim positioned between the outer surface of theinsert and the inner surface of the chamber to force contact between theouter surface of the insert and the inner surface of the chamber toestablish a snug fit therebetween for the shaft of the arrow.
 12. Anarrow as recited in claim 11 wherein the shim is a first shim and thearrow further comprises: a second shim affixed to the outer surface ofthe insert of the nock section to position the second shim between theouter surface of the insert and the inner surface of the chamber; and athird shim affixed to the outer surface of the insert of the nocksection to position the third shim between the outer surface of theinsert and the inner surface of the chamber, wherein the second shim andthe third shim cooperate with the shim to force contact between theouter surface of the insert and the inner surface of the chamber toestablish the snug fit therebetween.
 13. An arrow as recited in claim 11further comprising a mechanical stop, wherein the mechanical stopestablishes a limit for forward movement of the insert when the nocksection is engaged with the chamber of the tip section.
 14. An arrow asrecited in claim 13 wherein the mechanical stop is an annulus-shapedcollar affixed to the fore-end of the nock section adjacent the insert,wherein the collar has the diameter “D”.
 15. An arrow as recited inclaim 13 wherein the mechanical stop is an annulus-shaped interiorsleeve positioned inside the chamber of the tip section at a distance“L” from the aft-end of the tip section, wherein the sleeve has an innerdiameter “d_(s)” with “d_(s)” being less than “d_(i)”(“d_(s)”<“d_(i)”<“d_(c)”).
 16. An arrow as recited in claim 11 furthercomprising a first index mark formed onto the aft-end of the tip sectionfor alignment with a second mark formed onto the fore-end of the nocksection, to optimize aerodynamic performance of the arrow.
 17. A methodfor manufacturing and assembling a shaft of an arrow which comprises thesteps of: providing an elongated, tubular tip section defining an axisand having a fore-end and an aft-end, wherein the tip section has anouter diameter (D) and is formed with a hollow chamber at the aft-end,and wherein the chamber has a diameter “d_(c)” measured at an innersurface; forming an insert on a nock section having a fore-end and anaft-end, wherein the insert extends from the fore end of the nocksection in an axial direction through a distance “L”, wherein the insertof the nock section has an outer surface with a diameter of “d_(i)” with“d_(i)” being less than d_(c) (d_(i)<d_(c)) for insertion of the insertof the nock section into the chamber of the tip section; affixing a shimto the outer surface of the insert; incorporating a mechanical stop tointeract between the tip section and the nock section to limit insertionof the insert into the chamber; and inserting the insert of the nocksection into the chamber of the tip section to position the shim betweenthe outer surface of the insert and the inner surface of the chamber toforce contact between the outer surface of the insert against the innersurface of the chamber to establish a snug fit between the tip sectionand the nock section to assemble the shaft.
 18. A method as recited inclaim 17 wherein the mechanical stop is an annulus-shaped collar and theincorporating step further comprises the step of attaching the collar onthe fore-end of the nock portion adjacent the insert, wherein the collarhas the diameter “D”.
 19. A method as recited in claim 17 wherein themechanical stop is a tubular-shaped interior sleeve and theincorporating step further comprises the steps of: affixing the interiorsleeve into the chamber at the distance “L” from the aft-end of the tipsection; and establishing contact between the insert and the interiorsleeve to prevent further axial movement of the insert.
 20. A method asrecited in claim 17 further comprising the steps of: placing a firstindex mark onto the aft-end of the tip portion; and placing a secondmark onto the fore-end of the nock portion proximal the insert; andaligning the first mark with the second mark after the inserting step toassemble the arrow and optimize aerodynamic performance of the arrow.